Add events for datastore pre-drop, drop, and import

modules/datastore/datastore.services.yml

@@ -8,6 +8,7 @@ services:
       - '@dkan.datastore.import_job_store_factory'
       - '@dkan.datastore.service.resource_processor.dictionary_enforcer'
       - '@dkan.metastore.resource_mapper'
+      - '@event_dispatcher'
 
   dkan.datastore.service.post_import:
     class: \Drupal\datastore\Service\PostImport
@@ -58,6 +59,7 @@ services:
       - '@dkan.datastore.import_job_store_factory'
       - '@dkan.datastore.database_table_factory'
       - '@dkan.datastore.logger_channel'
+      - '@event_dispatcher'
 
   dkan.datastore.logger_channel:
     parent: logger.channel_base

modules/datastore/modules/datastore_mysql_import/datastore_mysql_import.services.yml

@@ -6,6 +6,7 @@ services:
       - '@dkan.datastore.import_job_store_factory'
       - '@dkan.datastore_mysql_import.database_table_factory'
       - '@dkan.datastore.logger_channel'
+      - '@event_dispatcher'
 
   dkan.datastore_mysql_import.database_table_factory:
     class: \Drupal\datastore_mysql_import\Storage\MySqlDatabaseTableFactory

modules/datastore/modules/datastore_mysql_import/src/Factory/MysqlImportFactory.php

@@ -8,6 +8,7 @@
 use Drupal\datastore_mysql_import\Service\MysqlImport;
 use Drupal\datastore_mysql_import\Storage\MySqlDatabaseTableFactory;
 use Psr\Log\LoggerInterface;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 
 /**
  * Mysql importer factory.
@@ -35,23 +36,30 @@ class MysqlImportFactory implements ImportFactoryInterface {
    */
   private LoggerInterface $logger;
 
+  /**
+   * Event dispatcher service.
+   *
+   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface
+   */
+  private EventDispatcherInterface $eventDispatcher;
+
   /**
    * Constructor.
    */
   public function __construct(
     ImportJobStoreFactory $importJobStoreFactory,
     MySqlDatabaseTableFactory $databaseTableFactory,
-    LoggerInterface $loggerChannel
+    LoggerInterface $loggerChannel,
+    EventDispatcherInterface $eventDispatcher,
   ) {
     $this->importJobStoreFactory = $importJobStoreFactory;
     $this->databaseTableFactory = $databaseTableFactory;
     $this->logger = $loggerChannel;
+    $this->eventDispatcher = $eventDispatcher;
   }
 
   /**
-   * Inherited.
-   *
-   * @inheritdoc
+   * {@inheritDoc}
    */
   public function getInstance(string $identifier, array $config = []) {
     $resource = $config['resource'] ?? FALSE;
@@ -63,7 +71,8 @@ public function getInstance(string $identifier, array $config = []) {
       $resource,
       $this->importJobStoreFactory,
       $this->databaseTableFactory,
-      $this->logger
+      $this->logger,
+      $this->eventDispatcher
     );
     $importer->setImporterClass(MysqlImport::class);
     return $importer;

modules/datastore/src/DatastoreService.php

@@ -2,22 +2,39 @@
 
 namespace Drupal\datastore;
 
-use Drupal\common\DataResource;
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\Core\Queue\QueueFactory;
+use Drupal\common\DataResource;
+use Drupal\datastore\Events\DatastoreDroppedEvent;
+use Drupal\datastore\Events\DatastorePreDropEvent;
 use Drupal\datastore\Service\Factory\ImportFactoryInterface;
 use Drupal\datastore\Service\ImportService;
 use Drupal\datastore\Service\ResourceLocalizer;
 use Drupal\datastore\Service\ResourceProcessor\DictionaryEnforcer;
 use Drupal\datastore\Storage\ImportJobStoreFactory;
 use Drupal\metastore\ResourceMapper;
 use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 
 /**
  * Main services for the datastore.
  */
 class DatastoreService implements ContainerInjectionInterface {
 
+  /**
+   * This event is triggered when the datastore is about to be dropped.
+   *
+   * The event data is a keyed array, identifier and version.
+   */
+  const EVENT_DATASTORE_PRE_DROP = 'dkan_datastore_pre_drop';
+
+  /**
+   * This event is triggered when the datastore is dropped.
+   *
+   * The event data is a keyed array, identifier and version.
+   */
+  const EVENT_DATASTORE_DROPPED = 'dkan_datastore_dropped';
+
   /**
    * Resource localizer for handling remote resource URLs.
    *
@@ -60,6 +77,13 @@ class DatastoreService implements ContainerInjectionInterface {
    */
   private ImportJobStoreFactory $importJobStoreFactory;
 
+  /**
+   * Event dispatcher service.
+   *
+   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface
+   */
+  private EventDispatcherInterface $eventDispatcher;
+
   /**
    * {@inheritdoc}
    */
@@ -70,7 +94,8 @@ public static function create(ContainerInterface $container) {
       $container->get('queue'),
       $container->get('dkan.datastore.import_job_store_factory'),
       $container->get('dkan.datastore.service.resource_processor.dictionary_enforcer'),
-      $container->get('dkan.metastore.resource_mapper')
+      $container->get('dkan.metastore.resource_mapper'),
+      $container->get('event_dispatcher')
     );
   }
 
@@ -89,21 +114,25 @@ public static function create(ContainerInterface $container) {
    *   Dictionary Enforcer object.
    * @param \Drupal\metastore\ResourceMapper $resourceMapper
    *   Resource mapper service.
+   * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $eventDispatcher
+   *   Event dispatcher service.
    */
   public function __construct(
     ResourceLocalizer $resourceLocalizer,
     ImportFactoryInterface $importServiceFactory,
     QueueFactory $queue,
     ImportJobStoreFactory $importJobStoreFactory,
     DictionaryEnforcer $dictionaryEnforcer,
-    ResourceMapper $resourceMapper
+    ResourceMapper $resourceMapper,
+    EventDispatcherInterface $eventDispatcher,
   ) {
     $this->resourceLocalizer = $resourceLocalizer;
     $this->importServiceFactory = $importServiceFactory;
     $this->queue = $queue;
     $this->importJobStoreFactory = $importJobStoreFactory;
     $this->dictionaryEnforcer = $dictionaryEnforcer;
     $this->resourceMapper = $resourceMapper;
+    $this->eventDispatcher = $eventDispatcher;
   }
 
   /**
@@ -217,13 +246,13 @@ public function getImportService(DataResource $resource): ImportService {
   /**
    * Returns the Data Dictionary fields.
    *
-   * @param string $identifier
+   * @param string|null $identifier
    *   A resource's identifier. Used when in reference mode.
    *
    * @return array|null
    *   An array of dictionary fields or null if no dictionary is in use.
    */
-  public function getDataDictionaryFields(string $identifier = NULL): ?array {
+  public function getDataDictionaryFields(?string $identifier = NULL): ?array {
     return $this->dictionaryEnforcer->returnDataDictionaryFields($identifier);
   }
 
@@ -242,9 +271,17 @@ public function drop(string $identifier, ?string $version = NULL, bool $remove_l
     $resource = $this->resourceLocalizer->get($identifier, $version);
 
     if ($storage = $this->getStorage($identifier, $version)) {
+      $this->eventDispatcher->dispatch(
+        new DatastorePreDropEvent($identifier, $version),
+        self::EVENT_DATASTORE_PRE_DROP
+      );
       $storage->destruct();
       $this->importJobStoreFactory->getInstance()
         ->remove(md5($resource->getUniqueIdentifier()));
+      $this->eventDispatcher->dispatch(
+        new DatastoreDroppedEvent($identifier, $version),
+        self::EVENT_DATASTORE_DROPPED
+      );
     }
 
     if ($remove_local_resource) {

modules/datastore/src/EventSubscriber/DatastoreSubscriber.php

@@ -167,6 +167,8 @@ public function drop(Event $event) {
     $resource = $event->getData();
     $id = md5(str_replace(DataResource::DEFAULT_SOURCE_PERSPECTIVE, ResourceLocalizer::LOCAL_FILE_PERSPECTIVE, $resource->getUniqueIdentifier()));
     try {
+      // @todo Check if the datastore exists before dropping. Don't log an
+      //   error if it wasn't there to begin with.
       $this->datastoreService->drop($resource->getIdentifier(), $resource->getVersion());
       $this->logger->notice('Dropping datastore for @id', ['@id' => $id]);
     }

modules/datastore/src/Events/DatastoreDroppedEvent.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace Drupal\datastore\Events;
+
+/**
+ * Event object for after we've dropped a datastore.
+ *
+ * @see \Drupal\datastore\DatastoreService::EVENT_DATASTORE_DROPPED
+ */
+class DatastoreDroppedEvent extends DatastoreEventBase {
+
+}

modules/datastore/src/Events/DatastoreEventBase.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Drupal\datastore\Events;
+
+use Drupal\Component\EventDispatcher\Event;
+
+/**
+ * Event base class for the datastore module.
+ */
+class DatastoreEventBase extends Event implements DatastoreEventInterface {
+
+  /**
+   * The datastore identifier.
+   *
+   * @var string
+   */
+  private string $identifier;
+
+  /**
+   * The datastore version.
+   *
+   * @var string|null
+   */
+  private ?string $version;
+
+  /**
+   * Constructor.
+   *
+   * @param string $identifier
+   *   The datastore identifier.
+   * @param string|null $version
+   *   (Optional) The datastore version.
+   */
+  public function __construct(string $identifier, ?string $version) {
+    $this->identifier = $identifier;
+    $this->version = $version;
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  public function getIdentifier(): string {
+    return $this->identifier;
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  public function getVersion(): ?string {
+    return $this->version;
+  }
+
+}

modules/datastore/src/Events/DatastoreEventInterface.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Drupal\datastore\Events;
+
+/**
+ * Event base class for the datastore module.
+ */
+interface DatastoreEventInterface {
+
+  /**
+   * Get the datastore identifier.
+   *
+   * @return string
+   *   The datastore identifier.
+   */
+  public function getIdentifier(): string;
+
+  /**
+   * Get the datastore version.
+   *
+   * @return string|null
+   *   The datastore version, or NULL if none was provided.
+   */
+  public function getVersion(): ?string;
+
+}

modules/datastore/src/Events/DatastoreImportedEvent.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace Drupal\datastore\Events;
+
+/**
+ * Event object for when a datastore has finished importing.
+ *
+ * @see \Drupal\datastore\Service\ImportService::EVENT_DATASTORE_IMPORTED
+ */
+class DatastoreImportedEvent extends DatastoreEventBase {
+
+}

modules/datastore/src/Events/DatastorePreDropEvent.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace Drupal\datastore\Events;
+
+/**
+ * Event object for when we're about to drop a datastore.
+ *
+ * @see \Drupal\datastore\DatastoreService::EVENT_DATASTORE_PRE_DROP
+ */
+class DatastorePreDropEvent extends DatastoreEventBase {
+
+}

modules/datastore/src/Service/Factory/ImportServiceFactory.php

@@ -6,6 +6,7 @@
 use Drupal\datastore\Storage\DatabaseTableFactory;
 use Drupal\datastore\Storage\ImportJobStoreFactory;
 use Psr\Log\LoggerInterface;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 
 /**
  * Create an importer object for a given resource.
@@ -33,31 +34,39 @@ class ImportServiceFactory implements ImportFactoryInterface {
    */
   private LoggerInterface $logger;
 
+  /**
+   * Event dispatcher service.
+   *
+   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface
+   */
+  private EventDispatcherInterface $eventDispatcher;
+
   /**
    * Constructor.
    */
   public function __construct(
     ImportJobStoreFactory $importJobStoreFactory,
     DatabaseTableFactory $databaseTableFactory,
-    LoggerInterface $loggerChannel
+    LoggerInterface $loggerChannel,
+    EventDispatcherInterface $eventDispatcher,
   ) {
     $this->importJobStoreFactory = $importJobStoreFactory;
     $this->databaseTableFactory = $databaseTableFactory;
     $this->logger = $loggerChannel;
+    $this->eventDispatcher = $eventDispatcher;
   }
 
   /**
-   * Inherited.
-   *
-   * @inheritdoc
+   * {@inheritDoc}
    */
   public function getInstance(string $identifier, array $config = []) {
     if ($resource = $config['resource'] ?? FALSE) {
       return new ImportService(
         $resource,
         $this->importJobStoreFactory,
         $this->databaseTableFactory,
-        $this->logger
+        $this->logger,
+        $this->eventDispatcher,
       );
     }
     throw new \Exception("config['resource'] is required");